WASHINGTON — Embattled presidential hopeful Herman Cain told his staff Tuesday that he was reassessing his campaign after allegations that he'd carried on a 13-year extramarital affair.

Cain, one of the top-tier Republican contenders in the 2012 field, repeated his denials from Monday, when Ginger White, an unemployed single mother from Atlanta, leveled the claim in a televised interview with Atlanta's Fox station WAGA.

"I deny those charges, unequivocally," Cain told his campaign staff, according to a transcript of the call, first reported by National Review Online. "That being said, obviously this is a cause for reassessment. ... We have to do a reassessment as to whether or not this is going to create too much of a cloud, in some people's minds, as to whether or not they would be able to support us going forth."

Cain is also the subject of earlier allegations that he'd sexually harassed several women in the 1990s while he was the head of the National Restaurant Association. He's denied those as well.

White's allegations Monday have added to the obstacles confronting his presidential effort, which were nowhere in sight a few weeks ago when his campaign suddenly soared.

Cain drew only 6 percent in a CNN national poll of Republican voters in early September. By mid-October, support for the charismatic former Godfather's Pizza chief executive had vaulted to 25 percent, putting him into a dead heat with front-runner Mitt Romney, a former Massachusetts governor.

Cain's backing dipped to 14 percent earlier this month after the sexual harassment claims emerged. But he remains in a four-way tie in Iowa with Romney, former House Speaker Newt Gingrich and U.S. Rep. Ron Paul of Texas, according to a recent Bloomberg News poll.

"He still has levels of support," said Republican pollster David Winston, a longtime ally of Gingrich. "There are all these accusations out there. I think what you're seeing the public doing in response is taking them seriously. It's also waiting for proof."

The tolerance of Republican voters could be tested, however. The first ballots to be cast in the presidential race will be Jan. 3 in Iowa. But if Cain's image becomes one of a lightning rod for trouble, he might not last that long.

"In the era of the 24-hour news cycles, blogs and cable TV, we have these popcorn candidates that emerge quickly, look big and seem to be substantial," said Matt Schlapp, a Republican strategist and former White House political director for President George W. Bush. "However, after the initial taste, they haven't worked out well over the course of this presidential season ... and we are not even at the rough and tumble part yet."

White said she made her allegations public because she didn't approve of the way Cain had treated the women who'd accused him of sexual harassment.

"It bothered me that they were being demonized ... they were treated as if they were automatically lying, and the burden of proof was on them," White said in the interview.

She also said that knowledge about her relationship with Cain had gotten out and the news media had begun to call: "I wanted to give my side before it was thrown out there and made out to be something filthy."

She produced cellphone bills showing dozens of calls to a number that she said was Cain's. After the station texted the number, Cain called back. In that exchange, according to the station, Cain said he knew White and had been trying to help with her financial troubles.

In an interview Monday on CNN, Cain said that he and White were friends, but he denied that they'd been involved romantically.

In Cain's call Tuesday to his staff, he said the campaign had undergone several periods of reassessment: after the Iowa and Florida straw polls and following the earlier accusations over sexual harassment, as well as over his ability to raise money.

He said that "if a decision is made, different than to plow ahead, you all will be the first to know."

Cain also talked about the emotional toll on his wife and family.

"Anytime you put another cloud of doubt, unfortunately, in the court of public opinion, for some people, you're guilty until proven innocent," he said. "And so the public will have to decide whether they believe her or whether they believe me. That's why we're going to give it time, to see what type of response we get from our supporters."